A high-temperature fuel heat sink evaporation cycle aircraft environmental control system and method

Abstract

The present application provides an environmental control system and method for a high-temperature fuel heat sink evaporation cycle aircraft, which belongs to the field of aerospace. The system includes a compressor, a first pressure condenser, and a second pressure condenser. The outlet of the middle section of the compressor is connected to the inlet of the second passage of the first pressure condenser, and the outlet of the rear section of the compressor is connected to the inlet of the second passage of the second pressure condenser. The first refrigerant enters the compressor, and the second refrigerant is output from the middle section of the compressor to the first pressure condenser, and the third refrigerant is output from the rear section of the compressor to the second pressure condenser; the outlet of the first passage of the first pressure condenser is connected to the inlet of the first passage of the second pressure condenser; the refrigerant output from the outlet of the second passage of the second pressure condenser is mixed with the refrigerant output from the outlet of the second passage of the first pressure condenser. The high-temperature fuel heat sink evaporation cycle aircraft environmental control system and method provided by the present application can improve the system power-to-weight ratio and the utilization efficiency of the fuel heat sink.

Description

Technical Field

[0001] The present application relates to the field of aerospace technology, and in particular to an environmental control system and method for a high-temperature fuel heat sink evaporation cycle aircraft. Background Art

[0002] The key measure to meet the high-power heat dissipation requirements of aircraft electronic equipment is to gradually replace the air cycle with the evaporation cycle, which usually uses fuel and ram air as heat sinks. As the speed of the aircraft increases, the restrictions on the use of ram air become more stringent, resulting in an increase in the fuel heat sink load and an increase in fuel temperature. Therefore, it is difficult for the conventional evaporation cycle to cool efficiently.

[0003] The use of a cascade evaporation cycle can improve the refrigeration performance under fuel temperature conditions, but its system power-to-weight ratio is low and the fuel heat sink is not fully utilized. The cascade cycle is equivalent to using two sets of single-stage evaporation cycles, and the reuse of high-quality components such as compressors is low, resulting in a low system power-to-weight ratio. Secondly, the condensation temperature of the high-pressure stage of the evaporation cycle is relatively high to achieve heat release to the high-temperature fuel. However, the temperature of the fuel is relatively low at the beginning of heat exchange, the heat transfer temperature difference between the fuel and the refrigerant is large, the heat transfer loss is high, and the low-temperature part of the fuel heat sink cannot be efficiently utilized. Summary of the invention

[0004] In view of this, the present application provides a high-temperature fuel heat sink evaporation cycle aircraft environmental control system and method, which can achieve component reuse of high-weight compressors and efficient utilization of high-temperature and low-temperature parts of the fuel heat sink, and improve the system power-to-weight ratio and fuel heat sink utilization efficiency.

[0005] Specifically, the present application is implemented through the following technical solutions:

[0006] In a first aspect, the present application provides a high-temperature fuel heat sink evaporation cycle aircraft environmental control system, the system comprising at least a compressor, a first pressure condenser, and a second pressure condenser, wherein the ambient pressure of the first pressure condenser is lower than the ambient pressure of the second pressure condenser;

[0007] The outlet of the middle section of the compressor is connected to the inlet of the second passage of the first pressure condenser, and the outlet of the rear section of the compressor is connected to the inlet of the second passage of the second pressure condenser. The first refrigerant enters the compressor, the second refrigerant is output from the middle section of the compressor to the first pressure condenser, and the third refrigerant is output from the rear section of the compressor to the second pressure condenser; the pressure of the second refrigerant is lower than that of the third refrigerant;

[0008] The first passage outlet of the first pressure condenser is connected to the first passage inlet of the second pressure condenser, wherein the fuel as a condensing agent flows through the first pressure condenser and the second pressure condenser in sequence, gradually increasing the temperature of the fuel;

[0009] The refrigerant output from the second passage outlet of the second pressure condenser is mixed with the refrigerant output from the second passage outlet of the first pressure condenser to form the first refrigerant which flows into the compressor.

[0010] A second aspect of the present application provides an environmental control method for an aircraft with a high-temperature fuel heat sink evaporation cycle, the method comprising:

[0011] Inputting the first refrigerant into a compressor, outputting the second refrigerant from the middle section of the compressor and outputting the third refrigerant from the rear section of the compressor;

[0012] The second refrigerant is input into the first pressure condenser for condensation, and the fuel absorbs condensation heat to reach a first temperature; the third refrigerant is input into the second pressure condenser for re-condensation, and the fuel absorbs condensation heat to reach a second temperature, wherein the second temperature is higher than the first temperature, and the ambient pressure of the first pressure condenser is lower than the ambient pressure of the second pressure condenser;

[0013] The second refrigerant and the third refrigerant are fed into the spray pipe at the same time after being processed, and the refrigerant pressure energy is recovered to increase the compressor inlet pressure; wherein the pressure of the processed third refrigerant is greater than the pressure of the processed second refrigerant.

[0014] The high-temperature fuel heat sink evaporation cycle aircraft environmental control system and method provided in the present application realizes the reuse of the low-pressure stage components of the compressor by outputting the second refrigerant to the first pressure condenser through the middle section bleed air of the compressor, avoids the addition of additional equipment to handle refrigerants with different pressure requirements, reduces the weight of the system, and thus improves the power-to-weight ratio of the system, and enables the compressor to reasonably handle the refrigerant at different stages, fully utilizing the working characteristics of the compressor, improving the utilization efficiency of its components, and helping to optimize the overall performance of the system while meeting the refrigeration requirements. In addition, the first pressure condenser and the second pressure condenser adopt different pressure environments, and the fuel flows through the two in turn. According to the characteristics of the gradual increase in fuel temperature, the condensation process of the refrigerant can be reasonably arranged. The second refrigerant exchanges heat with the relatively low temperature fuel in the first pressure condenser with lower pressure, and the third refrigerant exchanges heat with the fuel with increased temperature in the second pressure condenser with higher pressure, which reduces the heat transfer temperature difference in the initial stage of fuel heat exchange, reduces heat transfer losses, and improves the utilization efficiency of the fuel heat sink. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A structural diagram of the first embodiment of the high-temperature fuel heat sink evaporation cycle aircraft environmental control system provided by the present application;

[0016] Figure 2 This is a structural diagram of the second embodiment of the high-temperature fuel heat sink evaporation cycle aircraft environmental control system provided by this application;

[0017] Figure 3 This is a flow chart of Example 3 of the environmental control method for a high-temperature fuel heat sink evaporation cycle aircraft provided in this application.

[0018] Description of reference numerals:

[0019] 1- compressor; 2- first pressure condenser; 3- second pressure condenser; 4- first throttle valve; 5- nozzle; 6- subcooler; 7- evaporator; 8- second throttle valve. DETAILED DESCRIPTION

[0020] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0021] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0022] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0023] Specific embodiments are given below to introduce the technical solution of the present application in detail.

[0024] Figure 1 This is a structural diagram of the first embodiment of the high-temperature fuel heat sink evaporation cycle aircraft environmental control system provided by this application. Please refer to Figure 1 , the system provided in this embodiment at least includes a compressor 1, a first pressure condenser 2, and a second pressure condenser 3, wherein the ambient pressure of the first pressure condenser 2 is lower than the ambient pressure of the second pressure condenser 3;

[0025] The outlet of the middle section of the compressor 1 is connected to the inlet of the second passage of the first pressure condenser 2, and the outlet of the rear section of the compressor 1 is connected to the inlet of the second passage of the second pressure condenser 3. The first refrigerant S1 enters the compressor 1, and the second refrigerant S2 is output from the middle section of the compressor 1 to the first pressure condenser 2, and the third refrigerant S3 is output from the rear section of the compressor 1 to the second pressure condenser 3; the pressure of the second refrigerant S2 is lower than that of the third refrigerant S3;

[0026] The first passage outlet of the first pressure condenser 2 is connected to the first passage inlet of the second pressure condenser 3, wherein the fuel as a condensing agent flows through the first pressure condenser 2 and the second pressure condenser 3 in sequence, gradually increasing the temperature of the fuel;

[0027] The refrigerant output from the second passage outlet of the second pressure condenser 3 and the refrigerant output from the second passage outlet of the first pressure condenser 2 are mixed to form the first refrigerant S1 which flows into the compressor 1 .

[0028] It should be noted that the compressor is a key component in the refrigeration cycle system, and its main function is to compress the refrigerant, increase the pressure and temperature of the refrigerant, and provide conditions for subsequent condensation, throttling and evaporation processes. In the system provided in this application, a bleed air compressor is used, wherein the bleed air compressor has the function of drawing out part of the refrigerant from the middle of the compressor on the basis of the function of an ordinary compressor.

[0029] Specifically, during the pressurization process, the pressure and state of the first refrigerant S1 at different positions in the compressor 1 change, thereby realizing diversion. When the first refrigerant S1 is pressurized to a certain degree in the compressor 1, a part of the refrigerant is drawn out from the middle section of the compressor 1. This part of the drawn-out refrigerant becomes the second refrigerant S2 and is transported to the first pressure condenser 2. The remaining first refrigerant S1 continues to be further pressurized in the compressor 1 and is finally output from the rear section of the compressor 1. This part of the refrigerant is the third refrigerant S3, which is then transported to the second pressure condenser 3.

[0030] Refrigerants of different pressures are transported to condensers of different pressure environments in order to better match the working conditions of the condenser, achieve an efficient heat exchange process, and thus improve the performance and efficiency of the entire system. Refrigerants of different pressures have different saturation temperatures. Transporting them to condensers with matching pressures can maintain a smaller heat transfer temperature difference between the refrigerant and the cooling medium (such as fuel) in the condenser. In the heat exchange process, a smaller heat transfer temperature difference means a higher heat exchange efficiency. When the second refrigerant S2 enters the first pressure condenser 2 with a lower pressure, its lower temperature can effectively exchange heat with the relatively low temperature fuel in the initial stage, because the fuel temperature is also lower at this time, and the temperature difference between the two is moderate, so that heat can be smoothly transferred from the refrigerant to the fuel, causing the refrigerant to condense. Similarly, when the third refrigerant S3 enters the second pressure condenser 3 with a higher pressure, its higher temperature can continue to exchange heat with the fuel heated by the first pressure condenser 2. At this time, the fuel temperature has risen, and the temperature difference with the third refrigerant S3 can still be maintained in a suitable range, ensuring continuous and efficient heat transfer and achieving an efficient condensation process. If the refrigerant is not transported according to pressure matching, the heat transfer temperature difference between the refrigerant and the fuel will be too large or too small, affecting the heat exchange efficiency and thus reducing the performance of the entire system.

[0031] It should also be noted that the use of a bleed air compressor to draw out part of the refrigerant from the middle of the compressor 1 as the second refrigerant S2 and send it to the first pressure condenser 2, this design realizes the reuse of the low-pressure stage components of the compressor. In the traditional single-stage compression system, the compressor only performs a single compression function, while in this system, through the bleed air, the low-pressure stage of the compressor plays multiple roles in the processing of different refrigerant streams, improves the utilization efficiency of the components, avoids the need to add additional equipment to achieve similar functions, thereby reducing the weight of the system to a certain extent and helping to improve the power-to-weight ratio of the system. In addition, the bleed air operation reduces the flow rate of the high-pressure stage of the compressor. According to the working characteristics of the compressor, the reduction in flow rate helps to improve the performance of the high-pressure section. The third refrigerant S3 processed in the rear section of the compressor can more effectively increase the pressure during the compression process due to the relatively reduced flow rate, so that the output third refrigerant S3 has a higher pressure and temperature, which is more suitable for entering the second pressure condenser 3 for an efficient heat exchange process, further optimizing the energy transfer and conversion efficiency of the entire system.

[0032] In this way, on the one hand, unnecessary component redundancy in the system is reduced, and the complexity and potential failure points of the system are reduced; on the other hand, more efficient compression and heat exchange processes help to improve refrigeration efficiency, so that the system can more effectively utilize energy while meeting the high-power heat dissipation requirements of aircraft electronic equipment and adapt to the operating requirements of the aircraft under different working conditions. For example, when the flight speed changes, resulting in limited use of ram air and increased fuel heat sink load, it can still maintain good cooling effect and system stability.

[0033] Please continue to refer to Figure 1 The system provided in the present application also includes a subcooler 6, a first throttle valve 4, a second throttle valve 8, an evaporator 7 and a nozzle 5. The second passage outlet of the first pressure condenser 2 is connected to the inlet of the first passage of the subcooler 6, and the second refrigerant condensed by the first pressure condenser 2 is input into the subcooler 6; the second passage outlet of the second pressure condenser 3 is connected to the inlet of the second passage of the subcooler 6 via the first throttle valve 4, and the third refrigerant condensed by the second pressure condenser is input into the subcooler 6. Specifically, the second passage outlet of the second pressure condenser 3 is connected to the inlet of the first throttle valve 4, and the outlet of the first throttle valve 4 is connected to the inlet of the second passage of the subcooler 6.

[0034] Among them, the first throttle valve 4 connected between the second passage outlet of the second pressure condenser and the second passage inlet of the subcooler is mainly used to throttle and reduce the pressure of the third refrigerant flowing out of the second pressure condenser 3. During the throttling process, the pressure of the refrigerant drops rapidly. According to the thermodynamic properties of the refrigerant, the pressure reduction will cause the temperature to drop accordingly, so that the third refrigerant reaches a suitable state before entering the subcooler. In this way, the third refrigerant can better exchange heat with other media in the subcooler, improve the subcooling effect, and also prepare for the subsequent circulation flow in the system, ensuring that the pressure and temperature distribution of the refrigerant in the entire system meet the system design requirements to achieve efficient energy transfer and conversion.

[0035] Through the throttling effect of the first throttle valve, the flow rate of the third refrigerant can be adjusted according to the actual operating requirements of the system. Under different flight conditions of the aircraft, such as take-off, cruising, landing and other stages, the heat dissipation requirements of the electronic equipment will change. At this time, the flow rate of the third refrigerant can be changed by adjusting the opening of the first throttle valve to adapt to the changes in the system load. For example, when the aircraft is in a high-load operation state and the electronic equipment generates a large amount of heat that needs to be dissipated, the opening of the first throttle valve can be appropriately increased to increase the flow rate of the third refrigerant and improve the cooling capacity of the system; conversely, under low-load conditions, the opening can be appropriately reduced to reduce the flow rate to achieve energy-saving operation and improve the overall energy efficiency ratio of the system.

[0036] It should be noted that the refrigerant (the second refrigerant after condensation) flowing out of the first pressure condenser 2 and the refrigerant (the third refrigerant after condensation) flowing out of the second pressure condenser 3 have different temperatures, the temperature of the second refrigerant after condensation is relatively low, and the temperature of the third refrigerant after condensation is relatively high. Introducing them into different passages of the subcooler 6 can make full use of this temperature difference, form a more favorable temperature gradient inside the subcooler 6, and promote heat exchange. The higher temperature condensed third refrigerant releases heat in one passage, and the lower temperature condensed second refrigerant absorbs heat in another passage, making the heat exchange more sufficient and efficient. Compared with mixing them and then supercooling them, the temperature difference between the two refrigerants can be better utilized to achieve heat transfer, improve the overall heat exchange efficiency of the subcooler, reduce the energy loss caused by mixing, and ensure that each refrigerant can reach a better supercooling state in the subcooler, thereby improving the refrigeration performance of the system.

[0037] It should also be noted that the outlet of the first passage of the subcooler 6 is connected to the inlet of the second throttle valve 8, the outlet of the second throttle valve 8 is connected to the inlet of the evaporator 7, and the outlet of the evaporator 7 is connected to the first inlet of the nozzle 5, so that the second refrigerant flows into the nozzle 5 after being subcooled, throttled and evaporated. The nozzle 5 includes a first inlet, a second inlet and an outlet, and the second inlet is connected to the outlet of the second passage of the subcooler 6 to input the subcooled third refrigerant into the nozzle 5.

[0038] Among them, the second throttle valve between the outlet of the first passage of the subcooler and the inlet of the evaporator has a key function of throttling and reducing the pressure of the second refrigerant after being supercooled by the subcooler, so that it can quickly evaporate and gasify when entering the evaporator. During the throttling process, the pressure of the second refrigerant is greatly reduced, and the boiling point is also reduced, so that it absorbs heat from the surrounding environment (such as the air in the aircraft cabin or electronic equipment compartment) in the evaporator and gasifies, producing a cooling effect.

[0039] The second throttle valve 8 can accurately control the pressure and flow rate of the second refrigerant entering the evaporator to match the working characteristics of the evaporator 7. The heat exchange efficiency of the evaporator 7 is closely related to factors such as the flow rate and pressure of the refrigerant and the structural design inside the evaporator 7. Through the adjustment of the second throttle valve 8, it can be ensured that the second refrigerant evaporates in the evaporator 7 in the best state, fully utilize the heat exchange area of ​​the evaporator 7, realize an efficient heat exchange process, improve the cooling capacity output, and avoid abnormal operation of the evaporator caused by excessive or insufficient refrigerant flow, such as frosting, poor cooling effect, etc., to ensure the stable operation of the evaporator 7 and the overall performance of the system.

[0040] The evaporator is a key component in the system that absorbs heat. After being throttled and depressurized by the second throttle valve, the second refrigerant evaporates and gasifies in the evaporator, absorbing a large amount of heat from the surrounding environment, thereby reducing the temperature of the cooled space (such as the aircraft cabin, electronic equipment compartment, etc.) to achieve the purpose of refrigeration. During the operation of the aircraft, electronic equipment will continue to generate heat. The evaporator can effectively take away this heat, maintain the normal operating temperature of the equipment, prevent equipment failure due to overheating, and ensure flight safety. The evaporation process in the evaporator causes the refrigerant to change from liquid to gas, forming low-temperature and low-pressure refrigerant vapor. These vapors are then transported to the second inlet of the system's nozzle to participate in the subsequent circulation process.

[0041] It should also be noted that the supercooled third refrigerant is ejected into the supercooled second refrigerant (actually the refrigerant output by the evaporator) in the nozzle 5 to reduce the compression ratio of the compressor 1. Injection refers to the process in which the high-pressure refrigerant draws and drives the low-pressure refrigerant in the nozzle to mix the two. The ejection process enables the high-pressure refrigerant to use its own pressure energy to increase the pressure of the low-pressure refrigerant when mixed with the low-pressure refrigerant, rather than increasing its pressure by recompressing it with the compressor. This reduces the amplitude of the refrigerant pressure that the compressor needs to increase, thereby reducing the compression ratio of the compressor. A lower compression ratio means that the compressor consumes less power when working, improves the working efficiency of the compressor, reduces the energy consumption of the system, helps to improve the energy efficiency ratio of the entire system, and saves energy while meeting the refrigeration needs. Finally, the first refrigerant obtained after ejection is input into the compressor through the nozzle outlet to form a complete cycle.

[0042] The system provided in this embodiment realizes the reuse of low-pressure stage components of the compressor by utilizing the bleed air compressor, avoids the increase of system weight by additional equipment, improves the system power-to-weight ratio, and the bleed air operation reduces the flow rate of the high-pressure stage of the compressor. According to the working characteristics of the compressor, the reduced flow rate helps to improve the performance of the high-pressure section. In addition, the ambient pressures of the first pressure condenser and the second pressure condenser are different, and the fuel flows through the two in sequence. The design of the two-stage condenser and the fuel heat exchange process can reduce the heat transfer temperature difference in the initial stage of fuel heat exchange, reduce heat transfer losses, and improve the utilization efficiency of the fuel heat sink. Refrigerants of different pressures are transported to the condenser with matching pressure, so that the heat transfer temperature difference between the refrigerant and the fuel is maintained small, achieving pressure matching and efficient condensation. It should also be noted that the coordinated work of various components ensures the stability of the system and can effectively meet the environmental control requirements of the aircraft in a complex flight environment.

[0043] Figure 2 This is a structural diagram of the second embodiment of the high-temperature fuel heat sink evaporation cycle aircraft environmental control system provided by this application. Please refer to Figure 2On the basis of the above embodiment, the nozzle 5 is arranged between the compressor 1 and the first pressure condenser 2, the outlet of the evaporator 7 is directly connected to the inlet of the compressor 1, and the second passage outlet of the subcooler 6 is connected to the first inlet of the nozzle 5; the middle section outlet of the compressor 1 is connected to the second inlet of the nozzle 5, and the second refrigerant S2 flows into the nozzle 5; the outlet of the nozzle 5 is connected to the second passage inlet of the first pressure condenser 2.

[0044] Specifically, the first refrigerant enters the compressor, the second refrigerant output from the middle section of the compressor enters the nozzle through the second inlet of the nozzle, and flows into the first pressure condenser through the outlet of the nozzle; the third refrigerant output from the rear section of the compressor flows into the second pressure condenser; the refrigerant output from the first pressure condenser flows into the first passage of the subcooler and then flows into the second throttle valve and the evaporator through the cooler to form the first refrigerant that flows into the compressor; the refrigerant output from the second pressure condenser flows into the second passage of the subcooler through the first throttle valve, and then is output from the subcooler and flows into the nozzle through the first inlet of the nozzle.

[0045] It should be noted that in the second embodiment, the nozzle 5 is arranged between the compressor 1 and the first pressure condenser 2. This position change is different from the first embodiment. In the first embodiment, the nozzle is mainly used to mix the refrigerant after the subcooler and recover the pressure energy, while in this embodiment, the nozzle intervenes in the refrigerant process in advance. The outlet of the middle section of the compressor is connected to the second inlet of the nozzle, so that the second refrigerant flows into the nozzle first. This change allows the second refrigerant to have the opportunity to exchange energy or mix with other refrigerants or media before entering the first pressure condenser, thereby affecting the energy distribution and heat exchange process of the entire system.

[0046] The nozzle can make preliminary adjustments to the pressure and temperature of the second refrigerant in the new position by using its special structure and working principle. When the second refrigerant enters the nozzle, it may be affected by the airflow in the nozzle. For example, in the contraction section of the nozzle, the flow rate increases and the pressure decreases, which may cause some physical changes in the second refrigerant, such as flash evaporation, thereby changing its thermodynamic state. When the second refrigerant in this adjusted state enters the first pressure condenser, it can better match the environment in the condenser and improve the heat exchange efficiency of the first pressure condenser, because its pressure and temperature are closer to the optimal heat exchange conditions in the condenser, which is conducive to the transfer of heat from the refrigerant to the fuel and optimizes the utilization efficiency of the fuel heat sink.

[0047] It should also be noted that the outlet of the evaporator 7 is directly connected to the inlet of the compressor 1, and the refrigerant output from the second throttle valve 8 flows into the evaporator 7 and no longer passes through the nozzle 5 but directly enters the compressor 1. This change simplifies the path of the refrigerant from the evaporator to the compressor, reducing the pressure loss and energy loss of the refrigerant during the transmission process. In the first embodiment, after the refrigerant comes out of the evaporator, it needs to pass through the nozzle and other components before entering the compressor. In this process, due to factors such as pipeline resistance and friction inside the components, part of the refrigerant's energy will inevitably be consumed and its pressure will be reduced. In the second embodiment, the direct connection allows the refrigerant to enter the compressor at a relatively high pressure and energy state, reducing the suction pressure requirement of the compressor, thereby reducing the power consumed by the compressor to increase the refrigerant pressure and improving the working efficiency of the compressor. In addition, this direct connection method reduces the interference of external factors (such as changes in the working state of the nozzle, pipeline blockage, etc.) on the refrigerant entering the compressor because it reduces the intermediate links, and enhances the stability of the system cycle.

[0048] It should be noted that in the second embodiment, the refrigerant output from the first throttle valve 4 flows into the subcooler 6 and then flows into the nozzle 5 as an ejected stream, rather than as an ejected stream (different from the first embodiment). This change changes the energy exchange and mixing process in the nozzle 5, affecting the state of the refrigerant that finally flows out of the nozzle 5 and enters the first pressure condenser 2. The new ejection process may cause the pressure, temperature and velocity distribution of the refrigerant in the nozzle to be different, thereby affecting the heat exchange effect of the first pressure condenser and the performance of the entire system. By adjusting the ejected stream, the energy utilization and distribution in the system can be optimized to a certain extent to adapt to different working conditions.

[0049] The method provided in this embodiment optimizes the performance of the environmental control system of the high-temperature fuel heat sink evaporation cycle aircraft from multiple aspects by changing the connection relationship of components such as the nozzle, evaporator and subcooler and the flow process, including improving heat exchange efficiency, reducing energy consumption, enhancing system stability, etc., so as to better meet the environmental control needs of the aircraft under various operating conditions.

[0050] Corresponding to the aforementioned embodiment of an environmental control system for a high-temperature fuel heat sink evaporation cycle aircraft, the present application also provides an embodiment of an environmental control method for a high-temperature fuel heat sink evaporation cycle aircraft.

[0051] Figure 3 Please refer to the flowchart of the third embodiment of the high-temperature fuel heat sink evaporation cycle aircraft environmental control method provided by this application. Figure 3 , the method comprising:

[0052] S301. Input the first refrigerant into a compressor, and output the second refrigerant from the middle section of the compressor and the third refrigerant from the rear section of the compressor.

[0053] It should be noted that during the operation of the compressor, the pressure and temperature of the refrigerant are increased by compressing it. Part of the refrigerant is drawn out from the middle section as the second refrigerant, and its pressure is relatively low. This part of the refrigerant will be sent to the first pressure condenser for a preliminary condensation process. The remaining refrigerant continues to be pressurized in the rear section of the compressor to become the third refrigerant, which has a higher pressure and is suitable for more efficient condensation in the second pressure condenser. This diversion method can make full use of the working characteristics of the compressor at different stages, provide refrigerant of appropriate pressure according to the needs of subsequent condensers, improve the reuse rate of compressor components, and avoid setting up separate compressors for different pressure requirements, thereby reducing the weight of the system to a certain extent, improving the system power-to-weight ratio, and helping to optimize the performance and energy efficiency of the entire system.

[0054] S302, input the second refrigerant into the first pressure condenser for condensation, and the fuel absorbs the condensation heat to reach the first temperature; input the third refrigerant into the second pressure condenser for re-condensation, and the fuel absorbs the condensation heat to reach the second temperature, wherein the second temperature is higher than the first temperature, and the ambient pressure of the first pressure condenser is lower than the ambient pressure of the second pressure condenser.

[0055] It should be noted that when the second refrigerant enters the first pressure condenser for condensation, the fuel oil, as a condensing agent, absorbs the condensation heat of the refrigerant, and the temperature gradually rises to the first temperature. The ambient pressure of the first pressure condenser is relatively low, which matches the pressure and temperature characteristics of the second refrigerant, so that the condensation process can be carried out efficiently. Subsequently, the fuel oil with the temperature raised to the first temperature flows into the second pressure condenser, and continues to absorb the heat released by the third refrigerant during the condensation process, and the temperature further rises to the second temperature. Since the pressure of the third refrigerant is relatively high, its condensation temperature in the second pressure condenser is also relatively high, and it can effectively exchange heat with the fuel oil that has been heated by the first pressure condenser. Through this two-stage condensation process, the energy of the fuel oil heat sink is fully utilized, and the utilization efficiency of the fuel oil heat sink is improved. At the same time, according to the gradual increase in the fuel oil temperature, the condensation process of the refrigerant is reasonably arranged, the heat transfer temperature difference in the initial stage of the fuel oil heat exchange is reduced, the heat transfer loss is reduced, the entire heat exchange process is more efficient, the energy transfer and conversion mechanism of the system is optimized, and it is helpful to improve the cooling effect of the system and meet the requirements of high-power heat dissipation of aircraft electronic equipment.

[0056] S303, inputting the second refrigerant and the third refrigerant into the nozzle at the same time after being processed to recover the refrigerant pressure energy; wherein the pressure of the processed third refrigerant is greater than the pressure of the processed second refrigerant.

[0057] It should be noted that the second refrigerant and the third refrigerant are simultaneously input into the nozzle after being processed, and the method includes: pressurizing the third refrigerant; inputting the pressurized third refrigerant into the nozzle; inputting the second refrigerant into the nozzle after being processed, and using the nozzle to inject the processed second refrigerant; fusing the injected second refrigerant and third refrigerant to form a mixed first refrigerant; and inputting the first refrigerant into the first pressure condenser.

[0058] Specifically, the treated second refrigerant and the third refrigerant are simultaneously introduced into the nozzle, and the high-pressure third refrigerant is used to eject the low-pressure second refrigerant, so that the two are mixed in the nozzle to form the first refrigerant. In this process, the pressure energy of the high-pressure refrigerant can be recycled. When the high-pressure third refrigerant flows at a high speed in the nozzle, according to the Bernoulli principle, its pressure decreases, forming a low-pressure area, thereby sucking the low-pressure second refrigerant into the nozzle. In the nozzle, momentum exchange occurs between the two refrigerants, and finally they are mixed evenly. This ejection and mixing process not only realizes the recombination of the refrigerants and prepares them for the next cycle, but also increases the compressor inlet pressure. The higher compressor inlet pressure means that the compressor needs to do less work when compressing the refrigerant, reduces the compressor pressure ratio, improves the compressor's working efficiency, and thus reduces the system's energy consumption. By recycling the refrigerant pressure energy, the entire system is more efficient in energy utilization, enhances the system's performance and stability, and ensures that environmental control services can be continuously and effectively provided under various operating conditions of the aircraft.

[0059] In addition, it should be noted that a first pressure condenser is connected to a second pressure condenser, and fuel oil is input into the first pressure condenser for heat exchange, and fuel oil at a first temperature is input into the second pressure condenser for heat exchange, and fuel oil at a second temperature is output, and the temperature of the fuel oil at the second temperature is higher than that of the fuel oil at the first temperature.

[0060] It should be noted that the first pressure condenser is connected to the second pressure condenser, and the fuel exchanges heat in the two condensers in turn, so that the fuel temperature is gradually increased. This heat exchange sequence is designed based on the characteristics of the low initial temperature of the fuel. In the first pressure condenser, the fuel exchanges heat with the second refrigerant with lower pressure and temperature. At this time, the fuel temperature is low, and the temperature difference with the second refrigerant is moderate, which can effectively absorb heat and raise the fuel temperature to the first temperature. Then, the fuel with increased temperature enters the second pressure condenser and exchanges heat with the third refrigerant with higher pressure and temperature. Since the fuel temperature has increased, the temperature difference with the third refrigerant can still be maintained in a suitable range, and it continues to absorb heat efficiently, so that the fuel temperature is further increased to the second temperature. This gradual heat exchange method makes full use of the energy of the fuel heat sink in different temperature sections, avoids the problem of low heat exchange efficiency caused by excessive or small heat transfer temperature difference, improves the overall utilization efficiency of the fuel heat sink, optimizes the thermal management of the system, helps to improve the cooling performance of the system, and ensures the stable control of the internal ambient temperature of the aircraft.

[0061] Optionally, in combination with the relevant contents of the above-mentioned embodiment 2, the middle outlet of the compressor is connected to the second inlet of the nozzle so that the second refrigerant enters the nozzle, and the rear outlet of the compressor is connected to the first inlet of the nozzle after passing through the second pressure condenser, the first throttle valve and the subcooler, so that the third refrigerant flowing out of the rear outlet of the compressor enters the first inlet of the nozzle after being processed, so that the second refrigerant and the third refrigerant are mixed in the nozzle to form the first refrigerant.

[0062] When the outlet of the middle section of the compressor is connected to the second inlet of the nozzle, and the outlet of the rear section of the compressor is connected to the first inlet of the nozzle after passing through the second pressure condenser, the first throttle valve and the supercooler, the flow path of the refrigerant between the compressor and the nozzle is changed. This change affects the injection process in the nozzle and the refrigerant mixing effect. In Example 2, the second refrigerant first flows into the nozzle and mixes with the third refrigerant entering the first inlet of the nozzle. This new connection method adjusts the energy exchange and mixing mechanism in the nozzle, so that the mixing process of the second refrigerant and the third refrigerant in the nozzle changes, and the state of the first refrigerant finally formed will also be different. Specifically, by adjusting the pressure, temperature and velocity distribution in the nozzle, the injection efficiency can be improved, and the refrigerant pressure energy can be better recovered, thereby further reducing the compressor pressure ratio and increasing the compressor inlet pressure, so that the system can adapt to the needs more flexibly under different working conditions, improve the energy efficiency and stability of the entire high-temperature fuel heat sink evaporation cycle aircraft environmental control system, and provide more reliable and efficient environmental control guarantee for the aircraft.

[0063] The method provided in this embodiment achieves effective treatment of refrigerant and fuel through the synergy between the various steps and the optional optimization combined with the relevant contents of Example 2, improves the energy efficiency, refrigeration performance and stability of the system, and meets the environmental control requirements of the aircraft in a complex flight environment.

[0064] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A high-temperature fuel heat sink evaporation cycle aircraft environmental control system, characterized in that: The system comprises at least a compressor, a first pressure condenser, and a second pressure condenser, wherein the ambient pressure of the first pressure condenser is lower than the ambient pressure of the second pressure condenser; The outlet of the middle section of the compressor is connected to the inlet of the second passage of the first pressure condenser, the outlet of the rear section of the compressor is connected to the inlet of the second passage of the second pressure condenser, the first refrigerant enters the compressor, the second refrigerant is output from the middle section of the compressor to the first pressure condenser, and the third refrigerant is output from the rear section of the compressor to the second pressure condenser; The pressure of the second refrigerant is lower than that of the third refrigerant; The first passage outlet of the first pressure condenser is connected to the first passage inlet of the second pressure condenser, wherein the fuel as a condensing agent flows through the first pressure condenser and the second pressure condenser in sequence, gradually increasing the temperature of the fuel; The refrigerant output from the second passage outlet of the second pressure condenser is mixed with the refrigerant output from the second passage outlet of the first pressure condenser to form the first refrigerant which flows into the compressor.

2. The system according to claim 1, characterized in that The system further comprises a subcooler, The outlet of the second passage of the first pressure condenser is connected to the inlet of the first passage of the subcooler, and the second refrigerant condensed by the first pressure condenser is input into the subcooler; The second passage outlet of the second pressure condenser is connected to the second passage inlet of the subcooler, and the third refrigerant condensed by the second pressure condenser is input into the subcooler.

3. The system according to claim 2, characterized in that The system also includes a nozzle, The spray pipe comprises a first inlet, a second inlet and an outlet, wherein the first inlet is connected to the outlet of the first passage of the subcooler, and the subcooled second refrigerant is input into the spray pipe; The second inlet is connected to the outlet of the second passage of the subcooler to input the subcooled third refrigerant into the spray pipe; wherein, The supercooled third refrigerant ejects the supercooled second refrigerant in the nozzle to reduce the compression ratio of the compressor; and the outlet outputs the first refrigerant.

4. The system according to claim 3, characterized in that The system further comprises a first throttle valve, a second throttle valve and an evaporator; wherein, The first passage outlet of the subcooler is connected to the inlet of the second throttle valve, the outlet of the second throttle valve is connected to the inlet of the evaporator, and the outlet of the evaporator is connected to the first inlet of the nozzle, so that the second refrigerant flows into the nozzle after being subcooled, throttled and evaporated.

5. The system according to claim 4, characterized in that The second passage outlet of the second pressure condenser is connected to the inlet of the first throttle valve, and the outlet of the first throttle valve is connected to the inlet of the second passage of the subcooler, so that the third refrigerant flows into the subcooler after throttling.

6. The system according to claim 4, characterized in that The nozzle is arranged between the compressor and the first pressure condenser, the outlet of the evaporator is directly connected to the inlet of the compressor, and the second passage outlet of the subcooler is connected to the first inlet of the nozzle; The compressor middle section outlet is connected to the second inlet of the nozzle, and the second refrigerant flows into the nozzle; the nozzle outlet is connected to the second passage inlet of the first pressure condenser.

7. A high-temperature fuel heat sink evaporation cycle aircraft environmental control method, characterized in that: The high-temperature fuel heat sink evaporation cycle aircraft environmental control method is applied to the system according to any one of claims 1 to 6, and the method comprises: Inputting the first refrigerant into a compressor, outputting the second refrigerant from the middle section of the compressor and outputting the third refrigerant from the rear section of the compressor; The second refrigerant is input into the first pressure condenser for condensation, and the fuel absorbs condensation heat to reach a first temperature; the third refrigerant is input into the second pressure condenser for re-condensation, and the fuel absorbs condensation heat to reach a second temperature, wherein the second temperature is higher than the first temperature, and the ambient pressure of the first pressure condenser is lower than the ambient pressure of the second pressure condenser; The second refrigerant and the third refrigerant are processed and simultaneously fed into the nozzle to recover the refrigerant pressure energy; wherein the pressure of the processed third refrigerant is greater than the pressure of the processed second refrigerant.

8. The method according to claim 7, characterized in that A first pressure condenser is connected to a second pressure condenser. After the fuel oil is input into the first pressure condenser for heat exchange, the fuel oil at a first temperature is input into the second pressure condenser for heat exchange, and the fuel oil at a second temperature is output. The temperature of the fuel oil at the second temperature is higher than that of the fuel oil at the first temperature.

9. The method according to claim 7, characterized in that: The middle outlet of the compressor is connected to the second inlet of the nozzle, so that the second refrigerant enters the nozzle; the rear outlet of the compressor is connected to the first inlet of the nozzle after passing through the second pressure condenser, the first throttle valve and the subcooler, so that the third refrigerant flowing out of the rear outlet of the compressor enters the first inlet of the nozzle after being processed, so that the second refrigerant and the third refrigerant are mixed in the nozzle to form the first refrigerant.

10. The method according to claim 7, characterized in that The second refrigerant and the third refrigerant are simultaneously fed into the spray pipe after being processed, and the method comprises: pressurizing the third refrigerant; inputting the pressurized third refrigerant into the spray pipe; Inputting the processed second refrigerant into the spray pipe, and injecting the processed second refrigerant through the spray pipe; fusing the ejected second refrigerant and the third refrigerant to form a mixed first refrigerant; The first refrigerant is introduced into the first pressure condenser.

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